Mercedes W166 Trim Cover B Pillar Left N/S Door Molding Panel A1666900587

The Mercedes W166 Left B-Pillar Cover Trim is an original interior trim element designed for installation on the left side of the body in W166 series models. This factory-produced B-pillar trim provides an aesthetic finish, protects the body structure, and helps maintain a cohesive, organized cabin appearance in Mercedes vehicles.

Specifications and technical data

• SKU: A1666900587
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A1666900587
• Substitutable numbers: A1666900587, A 166 690 05 87
• Location on the vehicle: Left
• Category: Trim

Intended Use and Function of the Part

The Left B-Pillar Cover Trim is responsible for aesthetically concealing the structure of the center pillar on the driver's side. This element:

• visually tidies the space between the front and rear doors,
• creates a consistent trim line for the side upholstery,
• serves as a cover for structural components and seat belt mountings,
• contributes to acoustic comfort by limiting unwanted resonances within the pillar area.

Thanks to its precise fit to the W166 body geometry, the cover ensures proper adhesion to the car body and stable mounting in the factory attachment points.

Construction and Fit for Mercedes W166

This part belongs to the Cladding, Decorative Strips, and Decorations group, meaning it has been designed to maintain the interior's stylistic consistency. The cover's construction is profiled to the specific shape of the B-pillar in the Mercedes W166, allowing for:

• precise alignment with adjacent upholstery panels,
• correct edge routing relative to door seals,
• hassle-free service access after removal (e.g., for routing wiring harnesses or seat belt mounting components).

Its placement on the left side of the vehicle allows for unambiguous identification of the mounting position and minimizes the risk of errors when selecting parts.

Characteristics of an Original Used Part

As a part from the range of original Mercedes components, the B-pillar cover retains factory fitting parameters and compatibility with the body structure. The used nature of the part means it comes from disassembly, which translates in practice to:

• preservation of original mounting geometry and clips,
• color and texture consistency matching the factory finish of a given equipment version,
• possibility of installation without the need for structural modifications.

This type of solution is particularly beneficial for accident repairs, replacing damaged interior elements, or restoring a vehicle to a factory-like condition.

Application in Interior Repairs and Restoration

Replacing the left B-pillar cover is recommended in situations where the existing element has suffered mechanical damage, deformation, or significant wear and tear. Installing this trim allows for:

• restoring the aesthetics of the cabin's side area,
• completing a missing element after bodywork and paint repairs,
• maintaining visual consistency with other trim panels.

Thanks to its factory design, the cover works seamlessly with other interior components, facilitating installation and reducing the time required for fitting during service work.

Related Mercedes Interior Trim Elements

If you are planning a comprehensive repair or upgrade of the interior side area in your Mercedes and need other elements from the same group, such as covers, decorative strips, or additional decorations, check the available parts in the Mercedes Cladding, Decorative Strips, and Decorations category.

If you want to better plan the selection of original, used components for popular car models and compare the most frequently chosen solutions, our guide may be helpful: Best Used Car Parts – A Guide to the Most Frequently Chosen Original Parts.